210=8t+1t^2

Solution for 210=8t+1t^2 equation:

210=8t+1t^2

We move all terms to the left:

210-(8t+1t^2)=0

We get rid of parentheses

-1t^2-8t+210=0

a = -1; b = -8; c = +210;
Δ = b2-4ac
Δ = -82-4·(-1)·210
Δ = 904
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{904}=\sqrt{4*226}=\sqrt{4}*\sqrt{226}=2\sqrt{226}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-2\sqrt{226}}{2*-1}=\frac{8-2\sqrt{226}}{-2}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+2\sqrt{226}}{2*-1}=\frac{8+2\sqrt{226}}{-2}
$